Heat exchanger

ABSTRACT

Provided is a heat exchanger. The heat exchanger includes a plurality of refrigerant tubes through which a refrigerant flows, the plurality of refrigerant tube being disposed to be spaced apart from each other in one direction and a plurality of fins disposed between the plurality of refrigerant tubes. A distance between the fins disposed on a front end-side of the plurality of refrigerant tubes is greater than that between the fins disposed on a rear end-side of the plurality of refrigerant tubes.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. 119 and 35 U.S.C. 365 to Korean Patent Application No. 10-2014-0015898 (filed on Feb. 12, 2014), which is hereby incorporated by reference in its entirety.

BACKGROUND

The present disclosure relates to a heat exchanger.

Heat exchangers constitute a refrigeration cycle and allow a refrigerant to flow therethrough. Also, heat exchangers are heat-exchanged with air to cool or heat the air. Such a heat exchanger may be used in refrigeration devices of air conditioners or refrigerators to serve as a condenser or evaporator according to whether a refrigerant is condensed or evaporated by the heat exchanger.

The heat exchanger is classified into a fin-and-tube type heat exchanger and a micro-channel type heat exchanger according to its shape. The fin-and-tube type heat exchanger includes a plurality of fins and a tube passing through the fins and having a circular shape or a shape similar to the circular shape. The micro-channel type heat exchanger includes a plurality of tubes (flat tubes) through which a refrigerant flows and a fin disposed between the plurality of flat tubes. Also, in both of the fin-and-tube type heat exchanger and the micro-channel type heat exchanger, a refrigerant flowing into the tube or flat tube is heat-exchanged with an external fluid, for example, air, and the fin increases a heat exchange area between the refrigerant flowing into the tube or flat tube and the external fluid.

For example, a louver may be provided as a structure for increasing the heat exchange area on the fin. The louver may be formed by cutting or bending a portion of the fin. Also, a distance (stacked distance) between the stacked fins may be reduced by the louver.

In the heat exchanger according to the related art, condensate water may be frozen to form frost on a surface of the fin when the heat exchanger serves as the evaporator at a low temperature.

Particularly, in the whole structure of the heat exchanger, the frost may be more formed on a front end-side of the heat exchanger that contacts firstly the flowing air. This is done because a temperature difference between the air and the refrigerant at the front end-side is greater than that at a rear end-side of the heat exchanger, i.e., a condensed degree of the refrigerant is relatively large.

Also, when the louver is provided on the fin, the space between the tube disposed on the front end-side of the heat exchanger and the fin may be blocked by the frost due to the narrowed stacked distance.

As described above, if a large amount of frost is formed, the passage through which the air flows may be blocked to deteriorate the heat exchange efficiency, and a time taken to perform defrosting for the heat exchanger may increase.

SUMMARY

Embodiments provide a heat exchanger that is improved in structure to delay formation of frost.

In one embodiment, a heat exchanger includes: a plurality of refrigerant tubes through which a refrigerant flows, the plurality of refrigerant tube being disposed to be spaced apart from each other in one direction; and a plurality of fins disposed between the plurality of refrigerant tubes, wherein a distance between the fins disposed on a front end-side of the plurality of refrigerant tubes is greater than that between the fins disposed on a rear end-side of the plurality of refrigerant tubes.

The front end-side of the plurality of refrigerant tubes may define an upstream side with respect to a flow direction of air, and the rear end-side of the plurality of refrigerant tubes may define a downstream side with respect to the flow direction of the air.

The plurality of refrigerant tubes may include: a plurality of first tubes defining a first row; and a plurality of second tubes disposed on one side of the plurality of first tubes to define a second row, wherein the flow direction of the air may be directed from the plurality of first tubes to the plurality of second tubes.

The plurality of fins may include: a plurality of first fins coupled to the plurality of first tubes; and a plurality of second fins coupled to the plurality of second tubes, wherein a distance between the plurality of first fins may be greater than that between the plurality of second fins.

Each of the fins may include: a ruled surface extending in one direction between the plurality of refrigerant tubes; and a curved surface bent or curved from the ruled surface, the curved surface including a tube coupling part coupled to each of the refrigerant tubes.

The plurality of refrigerant tubes may include a first tube defining the front end-side thereof and a second tube defining the rear end-side thereof, and the number (FPI) of ruled surfaces of the fins coupled to first tube may be less than that of ruled surfaces of the fins coupled to the second tube with respect to preset lengths of the first and second tubes.

The number (FPI) of the ruled surfaces of the fins coupled to the first tube may be about 17 to about 18, and the number of ruled surfaces of the fins coupled to the second tube may be about 20 to about 22.

Each of the ruled surface and the curved surface may be provided in plurality, and a distance (2Fp₁) between the tube coupling parts disposed on two curved surfaces adjacent to each other may be twice as much as a distance (Fp₁) between two ruled surfaces adjacent to each other.

The plurality of fins may include: a first fin including a first fin-side louver; and a second fin disposed on one side of the first fin, the second fin including a second fin-side louver.

The first fin-side louver may include first and second louvers that are aligned from the upstream side to the downstream side, and a pitch (P2) of the second louver may be greater than that (P1) of the first louver.

In a distance (S) between the first fin-side louver and the second fin-side louver, a distance (S1) at the upstream side may be greater than that (S2) at the downstream side with respect to the flow direction of the air.

The distance (S) between the first fin-side louver and the second fin-side louver may gradually decrease from the upstream side to the downstream side with respect to the flow direction of the air.

Each of the fins may include a fin body and a plurality of louvers extending outward from one surface and the other surface of the fin body, and the plurality of louvers may include a plurality of one side louvers having a louver angle angled with respect to the fin body, which gradually increases from the upstream side to the downstream side with respect to the flow direction of the air.

The plurality of louvers may include a plurality of the other side louvers having a louver angle angled with respect to the fin body, which gradually decreases from the upstream side to the downstream side with respect to the flow direction of the air.

The plurality of one side louvers and the plurality of the other side louvers may be disposed to be spaced apart from each other on both sides of the fin body.

In another embodiment, a heat exchanger includes: first and second headers disposed to be spaced apart from each other; a plurality of first tubes extending between the first and second headers to guide a flow of a refrigerant; a plurality of second tubes spaced apart from one side of the plurality of first tubes to extend, thereby guiding the flow of the refrigerant; a first fin disposed in a space between the plurality of first tubes to roundly extend; and a second fin disposed in a space between the plurality of second tubes to roundly extend, wherein the first fin has a curvature radius different from that of the second fin.

The plurality of first tubes may define an upstream side in a flow direction of air, and the plurality of second tubes may define a downstream side in the flow direction of the air, and the first fin may have a curvature radius greater than that of the second fin.

The heat exchanger may further may include a plurality of louvers disposed on the first or second fin, wherein a pitch (P1) of the first louver disposed at the upstream side may be less than that (P2) of the second louver disposed at the downstream side with respect to a flow direction of air.

The plurality of louvers may include a first fin-side louver disposed on the first fin and a second fin-side louver disposed on the second fin, and in a distance (S) between the first fin-side louver and the second fin-side louver, a distance (S2) at the downstream side may be less than that (S1) at the upstream side with respect to the flow direction of the air.

The first or second fin may include a fin body and a plurality of louvers extending outward from one surface and the other surface of the fin body, wherein the plurality of louvers may include: a plurality of one side louvers having a louver angle angled with respect to the fin body, which gradually increases from the upstream side to the downstream side with respect to the flow direction of the air; and a plurality of the other side louvers having a louver angle angled with respect to the fin body, which gradually decreases from the upstream side to the downstream side with respect to the flow direction of the air.

The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of a heat exchanger according to a first embodiment.

FIG. 2 is a plan view of the heat exchanger according to the first embodiment.

FIG. 3 is a partial view of the heat exchanger according to the first embodiment.

FIG. 4 is a cross-sectional view taken along line I-I′ of FIG. 1.

FIG. 5 is a graph illustrating an effect in which frost formation is delayed by a fin according to the first embodiment.

FIG. 6 is a partial view of a heat exchanger according to a second embodiment.

FIG. 7 is a view of a fin according to the second embodiment.

FIG. 8 is a view of a fin according to a third embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, exemplary embodiments will be described with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, that alternate embodiments included in other retrogressive inventions or falling within the spirit and scope of the present disclosure will fully convey the concept of the invention to those skilled in the art.

FIG. 1 is a front view of a heat exchanger according to a first embodiment.

Referring to FIG. 1, a heat exchanger 10 according to a first embodiment includes a plurality of refrigerant tubes 100 (hereinafter, referred to as tubes) through which a refrigerant flows, a plurality of fins 200 stacked on the tubes 100, and two headers 30 and 40 connected to both ends of the tubes 100.

The plurality of tubes 100 are lengthily disposed with a predetermined length in parallel to each other in a horizontal direction and spaced apart from each other in a direction perpendicular to the longitudinal direction thereof. For example, each of the tube 100 may include a flat tube having a polygonal cross-section.

The plurality of fins 200 are disposed between the two tubes 100 adjacent to each other. The plurality of fins 200 may be bent or curved to increase a heat-exchange area.

The two headers 30 and 40 include a first header 30 and a second header 40 which are disposed to be spaced apart from each other. The tubes 100 may be connected between the first and second headers 30 and 40. Also, a flow space in which the refrigerant flows are defined in each of the first and second headers 30 and 40.

In FIG. 1, since each of the two headers 30 and 40 extends in a vertical (longitudinal) direction, the header may be called a “vertical header”. However, the extension direction of the header may not be limited to the above-described direction. For example, the header may extend in a horizontal direction. Here, the tube 100 may extend in the vertical (longitudinal) direction.

Baffles 35, 43, and 45 are disposed within the two headers 30 and 40. In detail, the baffles 35, 43, and 45 include a first baffle 35 disposed within the first header 30 and second and third baffles 43 and 45 disposed within the second header 40. The baffles 35, 43, and 45 may partition refrigerant passages within each of the headers 30 and 40 to guide the refrigerant within the headers 30 and 40 so as to flow into the tubes 100.

The heat exchanger 10 includes an inflow part 50 for guiding introduction of the refrigerant into the heat exchanger and a discharge part 60 for guiding discharge of the refrigerant passing through the heat exchanger 10. For example, the inflow part 50 and the discharge part 60 are provided in the second header 40, and the discharge part 60 may be disposed to be spaced upward from the inflow part 50.

FIG. 2 is a plan view of the heat exchanger according to the first embodiment, FIG. 3 is a partial view of the heat exchanger according to the first embodiment, and FIG. 4 is a cross-sectional view taken along line I-I′ of FIG. 1.

Referring to FIGS. 2 to 4, the heat exchanger 10 according to the first embodiment includes a plurality of tubes 110 and 120 that are arranged in two rows.

In detail, the plurality of tubes 110 and 120 include a plurality of first tubes 110 disposed between the first header 30 and the second header 40 and a plurality of second tubes 120 disposed adjacent to one side of the plurality of first tubes 110 between the first header 30 and the second header 40.

The plurality of first tubes 110 may constitute one row (a first row) and be spaced apart from each other in a vertical direction. Also, the plurality of second tubes 120 may constitute the other row (a second row) and be spaced apart from each other in the vertical direction.

The fins 200 may be disposed in a space part that is defined by the plurality of first tubes spaced apart from each other and a space part that is defined by the plurality of second tubes spaced apart from each other.

As illustrated in FIG. 2, a fluid (air) passing through the heat exchanger 10 may flow form the plurality of first tubes 110 to the plurality of second tubes 120. Thus, the plurality of first tubes 110 and the fins 200 coupled to the plurality of first tubes 110 may constitute a front end-side of the heat exchanger 10, and the plurality of second tubes 120 and the fins 200 coupled to the plurality of second tubes 120 may constitute a rear end-side of the heat exchanger 10.

The fins 200 are coupled to the plurality of first tubes 110 and the plurality of second tubes 120. In detail, the fins 200 include a first fin 210 disposed in the space between the plurality of first tubes 110 and a second fin 220 disposed in the space between the plurality of second tubes 120.

The first fin 210 includes a ruled surface 211 straightly extending in one direction, for example, in a vertical direction between the plurality of first tubes 110 and a curved surface 213 that is curved or bent with a predetermined curvature from the ruled surface 211. Also, the curved surface 213 includes a first tube coupling part 215 coupled to one surface of the first tube 110.

Since the first fin 210 is bent or curved several times to extend, each of the ruled surface 211, the curved surface 213, and the first tube coupling part 215 may be provided in plurality.

A first tube coupling part 215 of the plurality of first tube coupling parts 215 may be coupled to one first tube 110 of the two first tubes adjacent to each other, and the rest first tube coupling part 215 may be coupled to the other first tube 110 of the two first tubes 110 adjacent to each other.

A fin distance Fp₁ is defined. The fin distance Fp₁ may be understood as a distance between two ruled surfaces 211 adjacent to each other. Also, a distance spaced between the two adjacent first tube coupling parts 215 may correspond to twice as much as the fin distance 2Fp₁. Also, the shortest distance between the first tube coupling part 215 coupled to one first tube 110 and the first tube coupling part 215 coupled to the other first tube 110 that is disposed adjacent to the first tube coupling part 215 coupled to the one first tube 110 may be defined as the fin distance Fp₁.

Although only the structure of the first fin 210 is illustrated in FIG. 3, since the second fin 220 has the same structure as the first fin 210, descriptions with respect to the second fin 220 may be quoted from those of the first fin 210.

The fin distance Fp₁ of the first fin 210 may be greater than that Fp₂ of the second fin 220. That is, in the first and second tubes 110 and 120 having the same length, the number of first fin 210 coupled to the first tube 110 may be less than that of second fin 220 coupled to the second tube 120. Here, the “number” of fins may be understood as the number of ruled surfaces of the fins.

In the tubes having a predetermined length (for example, about 1 inch), the number of disposed fins may be called a fin per inch (FPI). For example, an FPI of the first tube side may be about 15 to about 17, and an FPI of the second tube side 120 may be about 20 to about 22.

That is, since the FPI values with respect to the first and second fins 210 and 220 vary, the first fin 210 coupled to the first tube 110 may have density less than that of the second fin 220 coupled to the second tube 120, and the curved surface 213 of the first fin 210 may have a curvature radius greater than that of the curved part of the second fin 220.

Referring to FIG. 4, since the plurality of first tubes 110 constitutes the front end-side of the heat exchanger 10, and the plurality of second tubes 120 constitutes the rear end-side of the heat exchanger 10, an air flow A may pass through the first tube 110 and then pass through the second tube 120. Thus, the first tube 110 may be called a front end-side tube of the plurality of tubes 110 and 120, and the second tube 120 may be called a rear end-side tube of the plurality of tubes 110 and 120.

Also, since the number of first fins 210 coupled to the first tube 110 is relatively less, the number of second fins 220 coupled to the second tube 120 is relatively large, a flow rate of the air passing between the plurality of first tubes 110 may be greater than that of the air passing between the plurality of second tubes 210.

That is, since the number of first fins 210 is relatively less, the heat transfer performance in the first tube 110 may be reduced somewhat. However, condensation in the first tube 110 or the first fin 210 may be prevented or delayed. Also, the heat transfer performance reduced at the first tube side may be compensated while the air flows into the rear end-side of the heat exchanger 10, i.e., the second tube side.

FIG. 5 is a graph illustrating an effect in which frost formation is delayed by a fin according to the first embodiment.

Referring to FIG. 5, the above-described effects may be verifiably described. As the FIP value decreases, a time taken to form frost on the tube or fin may increase. That is, the frost formation may be delayed. Here, the “frost formation” may represent an amount of frost formed above a predetermined level, for example, a blocked degree of a space between the tube and the fin over a preset degree by the frost.

In summary, the number FPI of fins 210 disposed on the front end-side of the heat exchanger, at which the frost is quickly formed, or a large amount of frost is formed, i.e., the first tube side may be reduced to delay the time taken to form the frost.

FIG. 6 is a partial view of a heat exchanger according to a second embodiment, and FIG. 7 is a view of a fin according to the second embodiment.

Referring to FIGS. 6 and 7, a heat exchanger 10 according to a second embodiment includes first and second tubes 310 and 320 that are spaced apart from each other and fins 400 stacked between the first and second tubes 310 and 320. As described in the first embodiment, each of the fins 40 may be bent or curved several times and include a ruled surface, a curved surface, and a plurality of tube coupling parts coupled to the first and second tubes 310 and 320.

The fin 400 may include a louver 450 having a portion that protrudes from one surface or the other surface of the fin 400. Here, the one surface may be a top surface of the first or second fin 410 or 420 illustrated in FIG. 7, and the other surface may be a surface opposite to the one surface.

The louver 450 may be formed by cutting at least a portion of the fin 400. Also, the louver 450 may be bent in one or the other direction to increase a contact area between air and the fin 400. The louver 450 may be provided in plurality, and the plurality of louvers 450 may be disposed to be spaced apart from each other. The air may flow along the louver 450 while passing through one side of the fin 400. For example, the air may flow from one surface to the other surface of the fin 400 or from the other surface to one surface of the fin 400 along the louver 450.

In detail, the fins 400 include first and second fins 410 and 420 that are spaced apart from each other. The first and second fins 410 and 420 may be understood as portions corresponding to the “ruled surface” described in the first embodiment.

The first fin 410 includes a first fin body 411 defining a flat surface and a plurality of fin-side louvers 460 extending outward from one surface and the other surface of the first fin body 411. The plurality of first fin-side louvers 460 include a first louver 461, a second louver 462, and a third louver 463 which are aligned from an upstream side to a downstream side with respect to a flow direction A of the air.

Here, the upstream side” may represent a direction in which the air is blown in, and the “downstream side” may represent a direction in which the air is blown out. That is, the upstream side may correspond to the front end-side of the heat exchanger 10, and the downstream side may correspond to the rear end-side of the heat exchanger 10.

Also, the second fin 420 includes a second fin body 421 defining a flat surface and a plurality of fin-side louvers 470 extending outward from one surface and the other surface of the second fin body 421. The plurality of second fin-side louvers 470 include a fourth louver 471, a fifth louver 472, and a sixth louver 473 which are aligned from the upstream side to the downstream side with respect to the flow direction A of the air.

The plurality of first fin-side louvers 460 may have lengths that gradually increase from the upstream side to the downstream side with respect to the flow direction A of the air.

Values of constitutions of the fin 400 will be defined. In the plurality of first fin-side louvers 460 or the plurality of second fin-side louvers 470, a distance from one end to the other end of each of the louvers 461, 462, 463, 471, 472, and 473 in the extension direction of the fin or the flow direction A of the air is defined as a pitch P.

Also, the first fin-side louver 460 may inclinedly extend with respect to the first fin body 411, and the second fin-side louver 470 may inclinedly extend with respect to the second fin body 421. Here, the inclined angle θ is defined as a “louver angle”.

Also, a distance between the first fin 410 and the second fin 410 adjacent to the first fin 410 is defined as a fin distance S. Here, the fin distance S may be understood as a distance between an end of the first fin-side louver 460 and an end of the second fin-side louver 470.

In the current embodiment, the pitch P of the fin 400 may gradually increase from the upstream side to the downstream side.

Thus, the pitch P2 of the second louver 462 may be greater than that P2 of the first louver 461, and the pitch P3 of the third louver 463 may be greater than that P2 of the second louver 462. Similarly, the pitch of the fifth louver 472 may be greater than that of the fourth louver 471, and the pitch of the sixth louver 473 may be greater than that of the fifth louver 472.

Also, since the pitch P of the fin 400 gradually increases from the upstream side to the downstream side, the fin distance S may gradually decrease from the upstream side to the downstream side. For example, as illustrated in FIG. 7, a distance S2 between an end of the third louver 463 and an end of the sixth louver 473 may be less than that S1 between the end of the first louver 461 and an end of the fourth louver 471.

Here, the distances S1 and S2 may be distances in a direction perpendicular to the first and second fins 410 and 420, respectively. Also, the distance S1 may be a front end-side distance of the first and second tubes 310 and 320 or the fin 400, and the distance S2 may be a rear end-side distance.

According to the above-described constitutions, since a fin distance at the upstream side in the air flow or the front end-side of the heat exchanger 10 is greater than that at the downstream side in the air flow or the rear end-side of the heat exchanger 10, the frost formation on the front end-side of the heat exchanger 10 may be prevented or delayed.

FIG. 8 is a view of a fin according to a third embodiment.

Referring to FIG. 8, a fin 500 according to a third embodiment includes a fin body 510 defining a flat surface and a plurality of louvers 520 extending outward from one surface or the other surface of the fin body 510.

The plurality of louvers 520 include a plurality of one side louvers 521, 522, and 523 disposed on one side of the fin body 510 and a plurality of the other side louvers 524, 525, and 526 disposed on the other side of the fin body 510. The plurality of one side louvers 521, 522, and 523 and the plurality of the other side louvers 524, 525, and 526 may be partitioned by an approximately central portion of the fin body 510.

The plurality of one side louvers 521, 522, and 523 include a first louver 521, a second louver 522, and a third louver 523 which are successively disposed to be spaced apart from each other from a front end-side to a rear end-side of the heat exchanger 10, i.e., from an upstream side to a downstream side with respect to a flow direction A of air.

The first louver 521, the second louver 522, and the third louver 523 may have louver angles θ different from each other. In detail, the louver angle θ of the first louver 521 may be angled at an angle θ1 with respect to the fin body 510, and the louver angle θ of the second louver 522 may be angled at an angle θ2 with respect to the fin body 510. Also, the louver angle θ of the third louver 523 may be angled at an angle θ3 with respect to the fin body 510. Where angles are defined as θ1<θ2<θ3.

That is, the louver angles θ of the first to third louvers 521, 522, and 523 gradually increase from the upstream side to the downstream side with respect to the flow direction A of the air. According to the above-described constitutions, a flow distance of the air flowing into the fin 500 may be lengthened to improve flow efficiency and heat transfer performance.

The fin 500 further includes a plurality of the other side louvers 524, 525, and 526 that are disposed to be spaced apart from each other on one side of the third louver 523. The plurality of the other side louvers 524, 525, and 526 include a fourth louver 524, a fifth louver 525, and a sixth louver 526 which are successively disposed to be spaced apart from each other from the upstream side to the downstream side with respect to the flow direction A of the air.

An approximately central portion of the fin body 510 is disposed between the third louver 523 and the fourth louver 524. That is, the plurality of one side louvers 521, 522, and 523 and the plurality of the other side louvers 524, 525, and 526 are disposed to be spaced apart from each other on both sides of the fin body 510.

The louver angles θ of the fourth, fifth, and sixth louvers 524, 525, and 526 may be different from each other. In detail, the louver angle θ of the fourth louver 524 may be angled at an angle θ4 with respect to the fin body 510, and the louver angle θ of the fifth louver 525 may be angled at an angle θ5 with respect to the fin body 510. Also, the louver angle θ of the sixth louver 526 may be angled at an angle θ6 with respect to the fin body 510 Where angles are defined as θ4>θ5>θ6.

That is, the louver angles θ of the fourth to sixth louvers 524, 525, and 526 gradually decrease from the upstream side to the downstream side with respect to the flow direction A of the air. According to the above-described constitutions, a flow distance of the air flowing into the fin 500 may be lengthened to improve flow efficiency and heat transfer performance.

According to the embodiments, since the plurality of fins disposed on the front end-side of the heat exchanger have a relatively wide distance therebetween in the flow direction of the air, the formation of the frost on the front end-side of the heat exchanger may be delayed.

Particularly, when the refrigerant tubes are arranged in two rows, the fins disposed on the first row of the refrigerant tubes that contact the air firstly may have a relatively wide distance therebetween, and the fins disposed on the second row of the refrigerant tubes that contact the air later may have a relatively narrow distance therebetween. Thus, the formation of the frost may be delayed while securing the heat transfer performance over a predetermined level.

Also, a pitch of the louver disposed on the fin may increase from the front end-side toward the rear end-side of the heat exchanger to cause the relative large louver distance between the adjacent fins at the front end-side of the heat exchanger. Thus, the frost formation on the front end-side of the heat exchanger may be delayed.

As described above, since the frost formation is delayed, the air flow may be improved to increase an amount of wind passing through the heat exchanger and reduce the pressure loss that affects the heat exchanger.

Also, since angles between the plurality of louvers disposed on the fins are different according to the flow direction of the air, the flow distance of the air may be lengthened, and thus the heat transfer performance may be improved when compared to the case in which the angles between the louvers are uniform.

Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art. 

What is claimed is:
 1. A heat exchanger comprising: a plurality of refrigerant tubes through which a refrigerant flows, the plurality of refrigerant tubes spaced apart from each other in one direction; and a plurality of fins disposed between the plurality of refrigerant tubes, wherein a distance between fins disposed on a front end-side of the plurality of refrigerant tubes is greater than a distance between fins disposed on a rear end-side of the plurality of refrigerant tubes.
 2. The heat exchanger according to claim 1, wherein the front end-side of the plurality of refrigerant tubes defines an upstream side with respect to a flow direction of air, and the rear end-side of the plurality of refrigerant tubes defines a downstream side with respect to the flow direction of air.
 3. The heat exchanger according to claim 2, wherein the plurality of refrigerant tubes comprise: a plurality of first tubes defining a first row; and a plurality of second tubes disposed on one side of the plurality of first tubes to define a second row, wherein the flow direction of air is directed from the plurality of first tubes to the plurality of second tubes.
 4. The heat exchanger according to claim 3, wherein the plurality of fins comprise: a plurality of first fins coupled to the plurality of first tubes; and a plurality of second fins coupled to the plurality of second tubes, wherein a distance between the plurality of first fins is greater than a distance between the plurality of second fins.
 5. The heat exchanger according to claim 1, wherein each of the plurality of fins comprises: a ruled surface extending in one direction between the plurality of refrigerant tubes; and a curved surface bent or curved from the ruled surface, the curved surface comprising a tube coupling part coupled to one of the plurality of refrigerant tubes.
 6. The heat exchanger according to claim 5, wherein the plurality of refrigerant tubes comprise a first tube defining the front end-side thereof and a second tube defining the rear end-side thereof, and an FPI number of ruled surfaces of fins coupled to the first tube is less than an FPI number of ruled surfaces of fins coupled to the second tube in predetermined lengths of the first and second tubes, wherein an FPI number is defined as the number of fins per inch.
 7. The heat exchanger according to claim 6, wherein the FPI number of ruled surfaces of fins coupled to the first tube is about 15 to about 17, and the number of ruled surfaces of fins coupled to the second tube is about 20 to about
 22. 8. The heat exchanger according to claim 5, wherein each of the ruled surface and the curved surface is provided in plurality, and a distance between tube coupling parts disposed on two curved surfaces adjacent to each other is twice as much as a distance between two ruled surfaces adjacent to each other.
 9. The heat exchanger according to claim 2, wherein the plurality of fins comprises: a first fin comprising a first fin-side louver; and a second fin disposed on one side of the first fin, the second fin comprising a second fin-side louver.
 10. The heat exchanger according to claim 9, wherein the first fin-side louver comprises first and second louvers, and a pitch of the second louver is greater than a pitch of the first louver.
 11. The heat exchanger according to claim 10, wherein a distance between the first fin-side louver and the second fin-side louver at the upstream side is greater than a distance between the first fin-side louver and the second fin-side louver at the downstream side.
 12. The heat exchanger according to claim 11, wherein the distance between the first fin-side louver and the second fin-side louver gradually decreases from the upstream side to the downstream side.
 13. The heat exchanger according to claim 2, wherein each of the fins comprises a fin body and a plurality of louvers extending from one surface of the fin body to an opposite surface of the fin body, and the plurality of louvers comprises a plurality of first side louvers having a louver angle angled with respect to the fin body, which gradually increases from the upstream side to the downstream side.
 14. The heat exchanger according to claim 13, wherein the plurality of louvers comprises a plurality of second side louvers having a louver angle angled with respect to the fin body, which gradually decreases from the upstream side to the downstream side with respect to the flow direction of the air.
 15. The heat exchanger according to claim 14, wherein the plurality of first side louvers and the plurality of second side louvers are spaced apart from each other by a central portion.
 16. A heat exchanger comprising: first and second headers spaced apart from each other; a plurality of first tubes extending between the first and second headers to guide a flow of a refrigerant; a plurality of second tubes extending between the first and second headers to guide the flow of the refrigerant and disposed on a side of the plurality of first tubes; a first fin disposed in a space between the plurality of first tubes and extending in a curved pattern; and a second fin disposed in a space between the plurality of second tubes and extending in a curved pattern, wherein the first fin has a curvature radius different from a curvature radius of the second fin.
 17. The heat exchanger according to claim 16, wherein the plurality of first tubes define an upstream side in a flow direction of air, and the plurality of second tubes define a downstream side in the flow direction of the air, and the curvature radius of the first fin is greater than the curvature radius of the second fin.
 18. The heat exchanger according to claim 16, further comprising a plurality of louvers disposed on the first and second fins, wherein a pitch of a first louver disposed at an upstream side is less than a pitch of the second louver disposed at a downstream side with respect to a flow direction of air.
 19. The heat exchanger according to claim 18, wherein the plurality of louvers comprises a first fin-side louver disposed on the first fin and a second fin-side louver disposed on the second fin, and a distance between the first fin-side louver and the second fin-side louver at the downstream side is less than a distance between the first fin-side louver and the second fin-side louver at the upstream side.
 20. The heat exchanger according to claim 16, wherein each of the first and second fins comprises a fin body and a plurality of louvers extending from one surface of the fin body to an opposite surface of the fin body, wherein the plurality of louvers comprises: a plurality of first side louvers having a louver angle angled with respect to the fin body, which gradually increases from an upstream side to a downstream side with respect to a flow direction of air; and a plurality of the second side louvers having a louver angle angled with respect to the fin body, which gradually decreases from the upstream side to the downstream side with respect to the flow direction of air.
 21. The heat exchanger according to claim 6, wherein each of the ruled surface and the curved surface is provided in plurality, and a distance between tube coupling parts disposed on two curved surfaces adjacent to each other is twice as much as a distance between two ruled surfaces adjacent to each other.
 22. The heat exchanger according to claim 7, wherein each of the ruled surface and the curved surface is provided in plurality, and a distance between tube coupling parts disposed on two curved surfaces adjacent to each other is twice as much as a distance between two ruled surfaces adjacent to each other. 